Commit b53e041d authored by Dale Zhao's avatar Dale Zhao Committed by Alex Deucher
Browse files

drm/amd/display: ensure dentist display clock update finished in DCN20 



[Why]
We don't check DENTIST_DISPCLK_CHG_DONE to ensure dentist
display clockis updated to target value. In some scenarios with large
display clock margin, it will deliver unfinished display clock and cause
issues like display black screen.

[How]
Checking DENTIST_DISPCLK_CHG_DONE to ensure display clock
has been update to target value before driver do other clock related
actions.

Reviewed-by: default avatarCyr Aric <aric.cyr@amd.com>
Acked-by: default avatarSolomon Chiu <solomon.chiu@amd.com>
Signed-off-by: default avatarDale Zhao <dale.zhao@amd.com>
Tested-by: default avatarDaniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
parent 8d177577

drivers/gpu/drm/amd/display/dc/clk_mgr/dcn20/dcn20_clk_mgr.c

+1 −1
Original line number Diff line number Diff line
@@ -197,7 +197,7 @@ void dcn20_update_clocks_update_dentist(struct clk_mgr_internal *clk_mgr, struct 


	REG_UPDATE(DENTIST_DISPCLK_CNTL,

			DENTIST_DISPCLK_WDIVIDER, dispclk_wdivider);

//	REG_WAIT(DENTIST_DISPCLK_CNTL, DENTIST_DISPCLK_CHG_DONE, 1, 5, 100);

	REG_WAIT(DENTIST_DISPCLK_CNTL, DENTIST_DISPCLK_CHG_DONE, 1, 50, 1000);

	REG_UPDATE(DENTIST_DISPCLK_CNTL,

			DENTIST_DPPCLK_WDIVIDER, dppclk_wdivider);

	REG_WAIT(DENTIST_DISPCLK_CNTL, DENTIST_DPPCLK_CHG_DONE, 1, 5, 100);